The present disclosure relates to a method of reducing buildup of insect residue and other matter on aerodynamic surfaces. More specifically, a subsurface topography is formed utilizing laser ablation micro-machining, and the substrate is then coated with an epoxy-based resin or other suitable material to provide a substantially smooth aerodynamic surface that reduces biological surface contamination while providing a smooth surface to reduce ice buildup and promote laminar flow.
Various aerodynamic shapes (e.g., airfoils) have been developed. These shapes may be configured to promote laminar flow over an aerodynamic surface to reduce aerodynamic drag.
However, in use, insect matter, ice, or other material may become adhered to the aerodynamic surface. This may create surface roughness that disrupts laminar flow over the aerodynamic surface. Various surface treatments have been developed in an effort to reduce or prevent buildup of insect matter, ice, and other substances on aerodynamic surfaces.
As discussed in U.S. Pat. No. 8,987,632, which is incorporated herein by reference in its entirety, interfacial interactions are governed by the surface energy of the contacting materials. The proclivity for favorable (adhesive or wetting) or (unfavorable adhesive or non-wetting) interactions will depend on the relative magnitude of these surface energies. As a result, the ability to controllably alter a material's surface energy is of great significance. Differences in the surface energy of materials can often be observed via water contact angle values.
Although laser ablation of a substrate to modify surface energy may reduce buildup of insect residue or the like on the treated surface, ice buildup on the surface may still occur (at least to some extent) due to the roughness of the treated/ablated surface. Also, because the ablated surface is not smooth, it may interfere with laminar flow over the surface if the surface comprised of the ablated surface is utilized for an airfoil or other aerodynamic surface.
Accordingly, materials having beneficial aspects of both topographically rich (rough) and smooth surfaces are desirable.